ALCOHOL-INSOLUBLE CONSTITUENTS OF JUICE VESICLES OF CITRUS FRUIT

SUMMARY– The texture of the edible portion of citrus fruit is determined by the characteristics of the juice vesicles and their insoluble constituents. Alcohol-insoluble solids (AIS) of the juice vesicles of several varieties of oranges, grapefruit and tangerines were studied at different stages of maturity. The protein content of the AIS as determined by the Kjeldahl method was found to decrease with fruit maturity, although total amount per fruit tended to increase. Polysaccharides were separated by extracting the AIS with alkali of various concentrations. Each fraction after hydrolysis was analyzed for the monomers both by paper chromatography and gas chromatography of the silylated derivatives. Galactose, arabinose and traces of glucose were found in fractions associated with galacturonic acid, and xylose, arabinose and glucose in different proportions were found in the hemicellulose and cellulose fractions. Traces of rhamnose and other uronic acids also were detected.     

烟草游离脯氨酸含量与雄性不育性的关系

对烟草雄性不育系和相应的保持系花蕾及叶片中游离脯氨酸的含量进行了分析。结果表明,花蕾中不育系的脯氨酸含量在小花蕾阶段与其保持系非常接近,但从中花蕾开始,保持系花蕾中的脯氨酸含量急剧上升,而不育系花蕾中的脯氨酸含量则基本保持稳定,因而,不育系花蕾中的脯氨酸含量在大花蕾时期明显低于其保持系;叶片中生育前期不育系的游离脯氨酸含量和相应保持系之间基本上没有大的差异,仅在生育后期存在一定的差异,但这些差异变化无规律性。因此,花蕾中游离脯氨酸含量与烟草雄性不育性有密切的关系,不育系花蕾中脯氨酸含量低是雄性不育性导致的结果;叶片中游离脯氨酸含量与烟草雄性不育性没有直接关系。     

Effects of pH, Storage Time and Temperature on the Tin Content of Single Strength Canned Grapefruit Juice

Grapefruit juice modified to pH 3.0, 3.5 and 4.0 and stored at 4, 21, 27, 32 and 38°C manifested a consistent two-stage pattern for tin uptake. The first stage consisted of a rapid (3 wk) uptake of tin (from 12 to approximately 100 ppm) and was relatively independent of juice pH or storage temperature. In the second stage, the increase in tin concentrations was extremely temperature dependent and only slightly pH dependent. Canned grapefruit juice should be stored below 27°C to insure tin contents do not exceed the Codex maximum of 250 ppm. In a survey of 55 commercially canned grapefruit juice samples stored 1-8 months under commercial conditions, tin concentrations ranged from 34-180 ppm.     

UCK2 promotes the proliferation,migration, and invasion of trophoblast cells in preeclampsia by activating the STAT3 pathway

Background: Preeclampsia (PE), characterized by hypertension and proteinuria, leads to serious maternal and infant complications. Uridine-cytidine kinase 2 (UCK2) belongs to the UCK family, a class of enzymes that catalyzes the conversion of uridine and cytidine to monophosphate form. However, the role of UCK2 in PE has not been reported. Methods: The expression of UCK2 was detected in the placenta of PE patients and N(ω)-nitro-L-arginine methyl esterinduced PE mouse model. Through forced up-regulation or down-regulation of UCK2 in vitro, we examined the effects of UCK2 on the proliferation, apoptosis, migration, and invasion of trophoblast cells. Stattic, the inhibitor of STAT3 pathway, was used to investigate whether the STAT3 pathway mediates the biological function of UCK2 in trophoblast cells. Results: The present study found that UCK2 showed low expression in the placenta of PE patients and PE mouse model. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and flow cytometry assays verified that up-regulation of UCK2 promoted the proliferation of trophoblast cells, while the silence of UCK2 suppressed cell proliferation. Besides, flow cytometry and TdT-mediated dUTP Nick-End Labeling assays demonstrated that knockdown of UCK2 resulted in apoptosis of trophoblast cells. The wound healing and transwell assays showed that the migration and invasion activities of the trophoblast cells were facilitated by the overexpression of UCK2 and were blocked by the silence of UCK2. Furthermore, the expression of phosphorylated STAT3 was increased with the upregulation of UCK2 and decreased with the inhibition of UCK2. When the STAT3 pathway was blocked by its inhibitor stattic, the promotion effects of UCK2 on trophoblast cells were suppressed. Conclusion: UCK2 promotes the proliferation, migration, and invasion of trophoblast cells, and these effects may be partly mediated by the activation of the STAT3 pathway.     

Expression profiles of circulating tRNA-derived small RNAs and their potential role in diabetes

Background: This work aimed to reveal the expression profiles of tRNA-derived small RNAs (tsRNAs) in diabetes. Methods: Thirty-five diabetes patients and thirty-three controls were enrolled. The serum samples of 4 diabetes patients and 4 controls were subjected to tRF and tiRNA polymerase chain reaction (PCR) Array analysis. Then quantitative PCR (qPCR) validation was performed on all the samples. Bioinformatics analyses were conducted to explore their functions. Results: We found 115 tsRNAs that significantly differed between the two groups. 3′tiR-080-ProTGG(mt) was selected for further qPCR validation in all participants, and it was significantly decreased in diabetes patients compared with controls. Bioinformatics analysis indicated that 3′tiR-080-ProTGG(mt) may play regulatory roles via the cyclic adenosine monophosphate (cAMP) signaling pathway in the pathogenesis and progression of diabetes. Conclusion: Hence, we report that circulating tsRNAs are dysregulated that could be involved in the pathogenesis of diabetes.     

Review on marine collagen peptides induce cancer cell apoptosis,necrosis, and autophagy by reducing oxidized free radicals

Marine collagen peptides (MCPs) are natural products prepared by hydrolyzing marine collagen protein through a variety of chemical methods or enzymes. MCPs have a range of structures and biological activities and are widely present in marine species. MCPs also have a small molecular weight, are easily modified, and absorbed by the body. These properties have attracted great interest from researchers studying antioxidant, anti-tumor, and anti-aging activities. MCPs of specific molecular weights have significant anti-tumor activity and no toxic side effects. Thus, MCPs have the potential use as anti-cancer adjuvant drugs. Free radicals produced by oxidation are closely related to human aging, cancer, arteriosclerosis, and other diseases, but their relationship with cancer is not well known. In this review, we focus on the antioxidant properties of MCPs in the treatment of cancer, highlighting their antioxidant molecular structure and potential for clinical practice.